The development and application of empirical models for the high SO2 concentration in urban areas.

The development of empirical models to describe extreme values of SO2 concentration directly from data collected over a 10-year period is described. A graphical method for the rapid calculation of high and maximum SO2 concentrations from the arithmetic mean of the concentrations recorded during the sampling period is reported. Applications of the resulting empirical models to the control of air quality and the planning and reduction of SO2 source emissions are illustrated. These applications are currently being developed by the Air Quality Control Authority of the Milan Area.